Apparatus for burning explosive gaseous mixtures



C. E. LUCKE.

APPARATUS FOR BURNING EXPLOSIVE GASEOUS MIXTURES.

APPLICATION FILEQ SEPT-2|. 1912.

Patented July 1, 1919.

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STATES PATENT OFFICE.

enemies E. LUCKE, or NEW YORK, 1i. Y., assiencn r0 GAS Ann OIL comnUsi'IoN comrm, or new roan, n. Y., A CORPORATION or nnmwmn.

APPARATUS FOR BURNING EXPLOSIVE GA SEOUS MIXTlJ'RES.

Specification of Letters Patent.-

' Patented July 1, 1919.

Application filed September 21, 1912. Serial No .,721,560.

To all whom it may concern:

Be it known that I, CHARLES E. LUcKn, a citizen of the United States, residin' at New York city, in the county of New ork and State of New York, have invented certain new and useful Improvements in .Apparatus for Burning Explosive Gaseous Mixtures, fully described and represented in the so as to prevent back flash, and then rapidly reducing the flow velocity to the rate of propagation of inflammation and prevent ing dissipation of the mixture or diflusion with other gas, and burning the mixture at the surface or zone where the velocity equals the rate a of propagation of inflammation. The invention aims to provide an apparatus of this kind which shall be adaptable to a great variety of uses, and shall be safe in operation, and which will permit of a large variation in supply pressure of the ex- 1 plosive mixture Without substantial change in location of the combustion zone, and which shall have a high capacity for the space occupied and shall be highly efficient.

To these ends, T provide a porous and permeable combustion bed or diaphragm and means for causing the gaseous mixture to enter the diaphragm and flow therethrough with an initial velocity greater than the rate of propagation of inflammation through the mixture, as by maintaining a supply of the explosive mixture against one side of the diaphragm under a suitable pressure; and I make the diaphragm of greater flow area, that is, with a greater aggregate cross-section of its passages or pores, toward the discharge side than toward the inlet side; and this result is secured in accordance with one feature of the present invention by making the diaphragm of increasing permeability in the direction from its inlet side or face to its discharge side, that is, the

aggregate cross-section of the passages or pores of the dlaphragm for a given cross- -sectional area is greater toward the outlet side than toward the inlet side of the diaphragm. The increase in permeability of the dlaphragm may be a gradual increase or an increase In one or more steps; and the diaphragm may be of any suitable construct1on to provide intercommunicating or expanding passages or passages which are both intercomniun-ioating and expanding, and may of any suitable refractory material, that is, material which will withstand the degree of heat to which it is subjected in the use of the apparatus.

In the accompanying drawings I have shown a simple form of apparatus made in accordance with the invention and modifications thereof. In said drawings:

Figure 1 shows partly in sectiona simple form of apparatus made in accordance with the invention. Figs. 2, 3, 1,5, 6 and 7 show modified forms of apparatus.

Referring first to 1B ig. 1, 10 represents a gas chamber one wall of which is formed by a porous and permeable diaphragm 11.

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The explosive gaseous mixture is supplied to the chamber 10 through a supply pipe 12 from a suitable source adapted to maintain the required pressure in the chamber 10. Any suitable means may be provided for supplying the explosive mixture. The simple means shown comprises a tank A for the air or other combustion supporting gas and a tank Gr for the fuel gas, from which tanks plpes 13 and 14 respectively lead to the pipe 12, said pipes 13 and 14 being controlled l'oy valves 15 and .16 respectively. A controlling valve 17 may also be. provided in the pipe 12. The supply of fuel gas and combustion supporting gas may be maintained in the respective tanks by any roe the diaphragm intended to be shown in this figure is one having intercommunicating passages. It'may be of any suitable character and formed in any suitable way from suitable refractoryfmaterial, as by bonding together," in a 'mold or otherwise, broken or other granular refractory material, or by molding a plastic mass to which has been added partlclesor pieces of matter which on being heated will disappear, or generate a gas or vapor, and leave a suitable porous and permeable structure.- In the operatlon of the apparatus, the proportionate amounts of fuel gas and air or otherc'ombustion supporting gas .fiowing. from the tanks'G and A throu h the pipe 12 into the gas chamber 10 will be controlled bythevalves 15 and 16 so that the mixture entering the chamber 10 will contain the fuel gas and combustion supporting gas in proportions to form an explosive mixture, and the amount of mixture entering the chamber will be controlled bythe valve 17 or by the valves '15 and 16 so as'to maintain a pressure within the chamber sufficient to cause the gaseous mixture passing from the chamber through the diaphragm 11 to flow through the passages at the inner or inlet side of the diaphragm with a velocity greater than the rate of propagation of inflammation through the mixture. .As the gas advances through the diaphragm its velocitywill be quickly reduced, and, being ignited, it will burn at the surface or zone where the velocity equals the rate of propagation of inflammation. This surface or zone of combustion will locate within the diaphragm a greater or less distance from the outer face thereof or at the outerv face,,according to the characterof the explosive mixture and according to the gas pressure maintained in the chamber 10 and the thickness and permeability .of the diaphragm. The proper proportions of fuel gas and air or other combustion supporting gas, that is, proportions such'according to the nature of the constituents that the gaseous mixture entering the cham-' ber 10 shall have 'theproperty of self-propa gation of inflammationand shall be of suitable strengthor richness within the limits within which the mixture will have the property of self-propagation of inflammation, and the propersupply of the mixture to the chamber to maintain the necessary or desired pressure therein, may be readily determined by experiment. The pressure of the fuel gas and' of the air or other combustion supporting gas in the tanks G and A respectively must, of. course, be kept sufli-.

cient' to' maintain the desired pressure in the gas chamber 10.

' Increase in the supply of mixture to the.

chamber 10 and increase in the pressure maintained in said chamber will causethe flame cap or combustion zone to advancethe inner face of the diaphragm that the inner face does not become heated to a degree suflicient to cause ignition of the mixture, back flash and ignition of the mixture in the chamber 10 will be prevented. As a safe-guard against ignition of the mixture in the chamber 10, however, during normal operation, and to prevent such ignition when the gas pressure. is reduced in shutting down or from any other cause, a flameinterrupting, cooling screen or partition 19 of one or more layers of fine wlre gauze or other suitable flame interrupting screen or partition may be provided in the chamber 10 adjacent to the inner face of the diaphragm. This flame interrupting screen is shown in Fig. 1 as set slightly away from the face of the diaphragm so as to avoid its becomin heated by contact therewith. It is not always necessary, however, that the flame interrupting screen, if provided, be set away from the face of the diaphragm, but it may set close thereagainst, and, furthermore, if the pores or passages in the innermost portion or layer of the diaphragm adjacent its inner face are sufii-' iciently small this portion of the diaphragmproper may itself form and serve, so long as 1t remains cool, as a flame interrupting screen to prevent transmission of inflammation to .the mixture within the chamber 10. It is desirable also when the side walls of the chamber 10 are of amaterial which is a good heat conductor to provide a suitable insulating joint as indicated at 20 between the part of the side walls in contact with the diaphragm and the part forming the side walls proper of the chamber.

By reason of the fact that at the combustion zone the temperature in the bed is high and at the supply side the temperature is comparatively low, there will be a conduction of heat through the bed toward the supply side which under some circumstances might raise the temperature of that side to the temperature of ignition of the mixture, igniting the mixture the feed chamber and interrupting the operation. It is found,

however, that when the permeability of the,

bed is low enough, its heat conductivity low enough, and the loss in pressure through thebed high enough, or the supply pressure high enough, that this does not take place.

Figs. 2 and 3 show eacha part of an apparatus similar to that shown in Fig. 1 but 'bility,

. llnFig. 2 the diaphragm is shown as made up of two porous and permeable layers or plates set one closely against the other, the inner plate a being of relatively less and the lltl dill

outer plate 0 of relatively greater permeability. e on plied to and malntained under suitable pressure in the chamber 10, itwill enter the diaphragm and flow through the passages of the inner plate a with a velocity greater than the rate of propagation of inflammation through the mixture; and in passing from the plate 0 into and through the outer plate 0 the mixture will lose velocity and will burn at the surface or zone within the outer plate 0 where equality is attained between the flow velocity and rate of propagation of inflammation. In Fig. 3 the diaphragm is shown as made up of three plates of porous and permeable refractory material 0, 0, '0, of successively greater permeability from the innermost one outward, so that the explosive mixture, entering and flowing through the inner plate with a velocity reater than the rate of propagation of in ammation, will enter and flow throu h the successive plates of increasing permea ility under decreasing ressure and with decreasing velocity until urned at the surface or zone where the velocity equals the rate of propagation of inflammation. The plates may be spaced slightly apart as shown in Fig. 3, but usually best results will be obtained with the plates set closely adjacent each other as in Fig. 2.

Fig. 42 shows a diaphragm or bed 11 formed by a mass of loose granular refractory material placed in a suitable container 21 formed with a gas chamber below a grate or other suitable perforate support 22 on which the granular material rests.

. The granular material is in comparatively lid till

smaller pieces at the bottom of the bed and of a larger size in the upper part of the bed; or the bed might be formed of granular material of gradually increasing size from the lower part up. A flame interrupting screen 19 is shown beneath the grate 22. I"

The bed or diaphragm as shown in, this figure is or greater crosssectional area toward its discharge side than toward the bottom or inlet side, and this might be de pended on to give the desired increase in flow area, or aggregate cross-section of the pores or passages of the bed, even though the granular material were of the same general size throughout the bed. A bed in which the increasing flow area is secured by both increase in cross-sectional area and increase .in permeability is, however, sometimes most desirable. Increasing the flow plosive mixture being sup-- Fig. l is gradual, but might, obviously, be

1n one or more steps. So, also, a gradual increase in cross-sectional area might be uni-' form instead of being sharper toward the discharge side of the bed as shown in this figure.

Fig. 5 shows a porous and permeable diaphragm of increasing permeability from its inner to its outer side or face made up of a,

plurality of plates 03 each havingmore or ess closely arranged perforations e. The aggregate capacity of the perforations of each successive plate from the inner plate outward is greater than that of the preced ing plate, and they are best arranged so that the perforations in adjacent plates do not register; and the aggregate capacity of the perforations in the innermost plate will be such compared with the supply or mixture to the supply chamber 10 that the mixture will flow through the perforations in this innermost plate d with a velocity greater than the rate of propagation of inflammation through the mixture, and by making the perforations in this innermost plate "sufficiently small this plate will act as a flame interrupting cooling screen. The plates 0? lltltll if the innermost plate is of metal, it is desirable that some additional means be revide'd for preventing the inner plate rom becoming too highly heated. For this purpose, I provide, as shown in this figure, the inner plate d with metal fingers or other suitable projections 25 which extend into contact with a body of water. The cooling, or heat absorbing, water might be arranged to circulate in contact with the conducting projections 25, butan efiicient arrangement is as shown in this figure where the lower part of the chamber 10 serves as a tank in which the water into which the lower ends of the conductors 25extend may be maintained at a suitable level by any suitable means. Such projections will not only prevent the plate from being injured by burning, but will also serve to keep the temperature of the gas passages of the mner plate and also of other plates conductively connected with the inner plate lower than it would otherwise be. They thus serve as an additional means of preventing premature ignition of the mixture by'heat conducted down from the hot zone. Such water cooled heat conducting llllli l'lllll llllt geously when the inner portion or the whole of the diaphragm is ofother material than metal.

To provide communication between the perforations in the successive plates, the plates are preferably made with surface grooves connecting the perforations anddicated being parallel grooves extendi at right angles to the grooves in the upper ace of the plate shown. I

The diaphragms shown in Figs. 1 to 5 have intercommunicating passages. ImFig. 7 I have shown a form of diaphragm in which there is no communication between the passages within the diaphragm, but the diaphragm is formed with a number of noncommunicating passages 7 extending through the diaphragm from its inner to its outer side, each of which expands or increases in cross-section in the direction from the inner to the outer side of the diaphragm. llhese expanding or conical passages allow the gas flowing through them to expand so as to advance in increasing volume and with decreasing velocity. The best results with a bed of this character are secured when the bed is formed with a comparatively large' number of openings f each of small capacity at its inlet end; and the angle of the conical or expanding openings should bef'very small and the diaphragm should be of consider 1. An apparatus for burning explosive gaseous mixtures com rising in combination a porous and permea le combustlon bed of greater permeability in one portion than in another, and means for causing theexplosive mixture to flow through the bed in the direction from the portion of lesser to the portion of greater permeability and with an initial velocity greater than the normal rate of propagation of inflammation of the mixture where it entersthe bed.

2. An apparatus for burning explosive gaseous mixtures com rising in comblnation a porous and permea le diaphra having intercommunicatin passages an being of increasing permea ihty and of increasing cross-sectional area in the direction from the inlet to the discharge side thereof, and means for maintaining a, comparatively slow moving supply of the explosive mixture against the inlet side of the diaphragm under suflicient'pressure to cause it to enter and move through the passages at the inlet side of the diaphragm with a velocity greater than the normal rate of propagation of inflammation of the mixture where it enters the diaphragm.

3.. An apparatus for burning explosive gaseous mixtures comprising in combination a gas chamber, a porous and permeable diaphragm forming the top wall of the gas chamber and formed by a. layer or bed of loose granular refractory material resting at the bottom on a support having gas passages therethrough, the granules at the bottom of said bed being smaller than those at and near theupper fac thereof, and means for maintainin a supply of the explosive mixture in sai .gas chamber under a pressure suflicient to cause the mixture to enter and to flow through the bed with an initial velocity greater than the normal rate of propagation of inflammation of the mixture where it enters the bed.

In testimony whereof I have hereuntoset m handin the presence of two subscribing witnesses.

. CHARLES E. LUCKE.

Witnesses:

FRANK C. ERB, A. L. IQENT." 

